Absolute Pixel sind nicht absolut

In the responses both on this blog (and on Slashdot), some people argued with the high DPI proposal saying »A pixel is just a pixel! Making a CSS pixel != screen pixel is a bad idea!« Those of you who think this way have a fundamental misunderstanding regarding how the Web works even today. It is already true that a CSS pixel does not necessarily equal a device pixel, and there’s nothing wrong with doing this. It doesn’t mess up your Web site. You don’t even have to think about it if you don’t want to. — CSS Units